真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)，這一(yi)術(shu)語譯自(zi)拉丁(ding)文vacuo，其(qi)意(yi)義是虛(xu)無。其(qi)實(shi)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)應理(li)解為(wei)(wei)氣(qi)體較稀薄的(de)(de)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)間(jian)。在(zai)指定的(de)(de)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)間(jian)內，低于一(yi)個大氣(qi)壓(ya)(ya)力的(de)(de)氣(qi)體狀(zhuang)態(tai)(tai)統稱(cheng)為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)。真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)狀(zhuang)態(tai)(tai)下(xia)氣(qi)體稀薄程(cheng)度(du)稱(cheng)為(wei)(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)度(du)（degreeofvacuum），通(tong)常用(yong)壓(ya)(ya)力值表示。因此真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)包(bao)(bao)(bao)(bao)裝(zhuang)實(shi)際(ji)上不(bu)是完全真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)的(de)(de)，采用(yong)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)包(bao)(bao)(bao)(bao)裝(zhuang)技術(shu)包(bao)(bao)(bao)(bao)裝(zhuang)的(de)(de)食品容器內的(de)(de)真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)度(du)通(tong)常在(zai)600-1333Pa。所(suo)以，又將真(zhen)(zhen)空(kong)(kong)(kong)(kong)(kong)(kong)(kong)包(bao)(bao)(bao)(bao)裝(zhuang)稱(cheng)為(wei)(wei)減(jian)壓(ya)(ya)包(bao)(bao)(bao)(bao)裝(zhuang)或(huo)排氣(qi)包(bao)(bao)(bao)(bao)裝(zhuang)。